Below is a list of common file types, extensions and uses for Graphic Design Professionals and their clients.
Raster File Types (definition here)
.jpg (.jpeg): Image File. Commonly used for photos but also acceptable for logo or advertisement files. While a .jpg will exclude some data, it is widely used and easily opened by most anyone with a computer. A jpg can be used for web (RGB, 72dpi) or print (CMYK, 300dpi), however any transparencies will be lost.
.psd: Adobe Photoshop Document. .psd’s are typically layered files in which designers can manipulate the text, images, shapes and format. These can be created in any size, resolution and colorspace.
.gif: Graphic Interchange Format File. These are primarily used in web and allow for transparencies as well as animation.
.png: Portable Network Graphic. These are often used in web-based design and applications but can also be supplied in CMYK/300dpi if intended for print use. These are easier to use in web as the transparencies remain intact and are of better quality than .giff’s.
.tif (.tiff): Tagged Image File. These files are the preferred file format for print designers as they are widely accepted by many of the design software programs and are equipped with all the file data. These can be RGB but are far more commonly used in print at CMYK/300dpi. These can be flat or layered depending on the intended use.
Vector File Types (definition here)
.eps: Encapsulated PostScript File. .eps files are often used for signs, banners, and billboards…or anything that is to be printed in large format. Vector graphics are easily scalable and can be used at any size without loss of image quality or definition. They can also be supplied to print designers for use in their designs, guaranteeing an image that prints clear and crisp.
.ai: Adobe Illustrator File. As the industry’s leader in software for creating vector graphics, Adobe Illustrator files are commonly used in the creation of logos by graphic designers all over the world. These files can also be supplied to printers for use when printing in large format or to other designers for creation of business collateral (advertisements, brochures, business cards, etc)
(as a side note, some .pdfs can also be used as vector files so long as they were developed in Illustrator (or other vector software) and saved properly for this use)
Page Layout File Types (definition here)
.indd: Adobe InDesign File. These are layout files with one or more pages arranged in a particular order.
.qxd: QuarkXPress File. Like .indd, these are layout files with one or more pages arranged in a particular order.
.pdf: Portable Document File. .pdf files are often used for print and are the preferred file type for magazines when accepting advertisements from designers and for printers when accepting magazine files for production. .pdfs are also viewable by most anyone with a computer or smartphone, making it the easily the best way to supply clients, printers or publications with a file to be proofed or printed. .pdfs are so versatile that they can be any color space, resolution or size and can be ‘flat’ (a single layer), merged (with transparency) or layered (for manipulation) making them acceptable for both print designers and web designers alike.
While there are many, many more file types that are used in design, these are some of the most common for print (which is of course what we specialize in). When in doubt, use the file type requested by your designer, publisher, printer or programmer. If they do not readily offer this information, just ask. Trust me, all of these folks will know what to ask for and what file type will make their job easier.